Is adding a lot of loop cuts bad?
It depends a lot on the situation and what you're modeling.

Generally, I try to get the main shape of my model in before adding in the subserf, and then once it's to the point where I need extra geometry, or smoothing, I'll add in the subserf, and start to add in holding edges.

If an edge loop isn't adding anything, get rid of it. Every vertex should have a purpose.

If you're getting to the point where you think that it's becoming a bit too messy, it could be a good idea to retopologize your mesh to streamline the topology.